Integrating the theme approach with aspectual scenarios

Dissertação de Mestrado em Engenharia InformáticaAspect-oriented requirements engineering emerged to deal with crosscutting requirements, i.e. requirements that are scattered in the requirements document and tangled with other requirements. There are several aspect-oriented requirements approaches - Theme, proposed by Baniassad and Clarke [7], is one of them. This approach is characterized by the identification of a set of actions associated to verbs present in requirements documentation. These actions are then analyzed in order to identify crosscutting behaviours, each one constituting a potential theme. One problem with this approach is that the composition mechanism is not expressive enough even when the Theme models are integrated to analysis models (e.g. UML diagrams). The MATA approach [24] provides powerful composition mechanisms, based on graph transformations that used UML models, in particular behaviour models (e.g. sequence or activity like diagrams). These models express scenarios that constitute a very popular and used technique to specify a system’s behaviour. Therefore, the result of the integration of these two approaches will be synergetic. Also, considering that in a system not only the expected situations happen, scenarios can also be used to illustrate unexpected situations, making their treatment possible. Negative scenarios are thus also considered, besides the positive ones: their representation is similar, only differing from an optimist and mostly assumed vision of the system’s behavior. These scenarios could be identified with Theme and mapped into MATA. In summary, the objective of this dissertation is twofold: firstly, we will integrate Theme with Aspectual Scenarios (specified in MATA); secondly, we will extend Theme to include the modeling of negative scenarios. The result will be the synergy between two complementary techniques, including the specification of undesirable situations, where behavioral and structural aspect modeling are integrated

First scientific observations with MEGARA at GTC

On June 25th 2017, the new intermediate-resolution optical IFU and MOS of the 10.4-m GTC had its first light. As part of the tests carried out to verify the performance of the instrument in its two modes (IFU and MOS) and 18 spectral setups (identical number of VPHs with resolutions R=6000-20000 from 0.36 to 1 micron) a number of astronomical objects were observed. These observations show that MEGARA@GTC is called to fill a niche of high-throughput, intermediateresolution IFU and MOS observations of extremely-faint narrow-lined objects. Lyman-α absorbers, star-forming dwarfs or even weak absorptions in stellar spectra in our Galaxy or in the Local Group can now be explored to a new level. Thus, the versatility of MEGARA in terms of observing modes and spectral resolution and coverage will allow GTC to go beyond current observational limits in either depth or precision for all these objects. The results to be presented in this talk clearly demonstrate the potential of MEGARA in this regard